[bluedino]

I don't remember doing that when I worked there. But plenty of people would try that exact scam, or buy something and then use the receipt to try to return the same item that they just grabbed off a shelf.

[ChrisMarshallNY]

I think they only started doing that, in the last few years.

The red tag has a barcode (and nothing else). They have a strip of them, next to the register.

You hand them the item, they tear off the bottom of the price tag, stick on the red tag, then scan it.

[yardstick]

So this also means you cannot return something without the red tag still intact?

[ChrisMarshallNY]

I don’t know.

I suspect you don’t need the tag, but you’ll need the receipt, otherwise.

[specialist]

That (obvious) strategy would have never occurred to me. I's make a terrible criminal (or pentester).